These bars tend to have 7 grams of protein and 4 grams of fiber per bar, and their percentage of calories from sugar hovers around 30%. Fat content tends to be 4-5 grams, while saturated fat ranges from 0.5 to 2 grams per bar.

These bars, which contain whole grains, bran, and soy protein concentrate, score high in fiber and protein. But the sugar and saturated fat are high -- around 47% calories from sugar and 3 grams of saturated fat per bar.

Luna bars score great for protein and sugar, but their fiber doesn't get to the 3-grams-or-more level. Most of the flavors have 2 grams of fiber, 10 grams of protein, around 27% calories from sugar, and 4.5 grams of fat (3.5 grams of saturated fat) per bar.

These come packaged as two bars per serving. They have 4-5 grams of protein, and are among the bars with the least amount of sugar (around 24% calories from sugar), but they have only 2 grams of fiber per serving.

These bars all contain 4 grams of protein, are low in saturated fat (1 gram), and have at least 2 grams of fiber. But the percentage of calories from sugar ranges from 34 to 38%, depending on the flavor.